Water hardness in Olympia
3.4 gpg soft
Tap water in Olympia is soft: 3.4 gpg (58 mg/L · 3.2 °dH · 5.8 °fH).
Source: City of Olympia Public Works, Drinking Water Quality page (2026) · data checked 2026-10-20
Range across supply zones: 55–60 mg/L.
Olympia gets its drinking water from groundwater. The city's water quality page describes it as slightly hard at 55-60 mg/L (about 3.2-3.5 gpg), a range rather than an average. The same page's classification table gives a wider band for slightly hard, and it does not explain the difference. The page is undated, so treat the figure as approximate.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 3.4 gpg |
|---|
How Olympia compares
- Tap water in Olympia is 63 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1193 of 1372 in the United States (1 = hardest); 13 % of these cities have softer water.
- In Washington it is number 12 of 27 cities; the regional median is 2.8 gpg.
- Nearest city with clearly softer water: Tacoma, 42 km away (1.9 gpg).
- Nearest city with clearly harder water: Lacey, 6 km away (4.4 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Little or no limescale in kettles, water heaters or washing machines.
- Soap lathers easily; water does not dry skin or hair.
- Dishwasher: salt setting at minimum or off.
- No softener needed; a jug filter only changes taste.
How much salt will you use for softening?
No. Water this soft does not need softening.
Descale a coffee machine or kettle about every 6 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Olympia
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 3 °dH |
| AEG / Electrolux | 1 |
| Beko | 1st |
| Hoover | S0 |
| LG | H0 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Olympia water hard or soft?
It is soft: 58 mg/L as CaCO₃ (3.4 gpg, 3.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Olympia safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Olympia water?
3.4 gpg, equal to 3.2 °dH, 5.8 °fH or 58 mg/L calcium carbonate.
What dishwasher salt setting should I use in Olympia?
For 58 mg/L (3.2 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Olympia?
No. With soft water a softener adds nothing.
Source
Source: City of Olympia Public Works, Drinking Water Quality page (2026). Method: computed from supplier's calcium and magnesium. City of Olympia Public Works, Drinking Water Quality page · Outdated figure? Tell us